Salvianolic acid A provides neuroprotective effects on cerebral ischemia-reperfusion injury in rats via PKA/CREB/c-Fos signaling pathway

Cerebral ischemia-reperfusion injury (CIRI) is a phenomenon that pathological injury of ischemic brain tissue is further aggravated after the restoration of blood supply. The complex pathological mechanism of CIRI has led to the failure of multiple neuroprotective agents in clinical studies. Salvianolic acid A (SAA) is a neuroprotective extract from Salvia miltiorrhiza Bge., with significant pharmacological activities in the treatment of brain injury. However, the neuroprotective mechanisms of SAA remain unclear. To explore the potential protective effect of SAA on CIRI and its mechanism, and to provide experimental basis for the research of new drugs for CIRI. A model of transient middle cerebral artery occlusion (tMCAO) in rats was used to simulate clinical CIRI, and the neuroprotective effect of SAA on tMCAO rats was investigated within 14 days after reperfusion. The improvement effects of SAA on cognitive impairment of tMCAO rats were investigated by behavioral tests from days 7-14. Finally, the neuroprotective mechanism of SAA was investigated on day 14. The neuroprotective effects and mechanism of SAA were investigated by behavioral tests, HE and TUNEL staining, RNA sequence (RNA-seq) analysis and Western blot in tMCAO rats. The brain protective effects of SAA were achieved by alleviating cerebral infarction, cerebral edema, cerebral atrophy and nerve injury in tMCAO rats. Meanwhile, SAA could effectively improve the cognitive impairment and pathological damage of hippocampal tissue, and inhibit cell apoptosis in tMCAO rats. Besides, SAA could provide neuroprotective effects by up-regulating the expression of Bcl-2, inhibiting the activation of Caspase 3, and regulating PKA/CREB/c-Fos signaling pathway. SAA can significantly improve brain injury and cognitive impairment in CIRI rats, and this neuroprotective effect may be achieved through the anti-apoptotic effect and the regulation of PKA/CREB/c-Fos signaling pathway.